Soil health evaluation in peri-urban farms irrigated with diverse wastewater sources
摘要
Soil health in peri-urban farms is significantly degraded by heavy metal-polluted irrigation water, disrupting soil physio-biochemical indicators and retarding plant growth. The present study was conducted to evaluate pollution level in wastewater and soil samples collected from ten critical pollution hotspots in Faisalabad to check the soil health properties. Thirty soil samples and ten wastewater samples were collected from ten peri-urban farms to assess contamination variability. Wastewater samples were analyzed for basic pollution indicators and results showed irrigation with mixed wastewater had higher pollution levels. Each soil sample was the composite of three replicates and collected from the depths of (0–15 cm) and were quantitatively analyzed for physicochemical and biological parameters including organic matter (0.9–1.91%), soil organic carbon (0.59–1.91), microbial biomass carbon (176.23–436.4 mg kg−1), phosphorous (13.5–43.6 mg kg−1) and nitrogen (20.43–70.37 mg kg−1), soil respiration (1.41–3.37 CO2 m−2 s−1), dehydrogenase (23.64–45.69 mg TPF kg−1 h−1), urease (3.6–9.63 mg NH4-N kg−1 h−1) and phosphatase (13.93–38.24 mg PNP kg−1 h−1) using standard analytical methods to evaluate soil health. Soil heavy metal analysis revealed pollution in all farms, with some exceeding permissible limits. The highest recorded values were; Cd, Pb, Cr, Ni, Cu and Mn 6.73, 72.84, 179.94, 18.53, 34.64 and 168.76 mg kg−1 respectively. These findings highlight the need for robust environmental policies, including mandatory industrial wastewater treatment and regular soil and water quality monitoring.